JP2023167366A - Image formation apparatus - Google Patents

Abstract

To prevent dew condensation from adhering to a conveyance path on the downstream side of a heating roller.SOLUTION: An image formation apparatus comprises: a heating roller which includes a heater; a pressure roller which presses a sheet against the heating roller to discharge the sheet; a conveyance path in which the sheet discharged from the heating roller and the pressure roller is conveyed; a first suction fan which is provided so as to interpose the conveyance path in a space with the heating roller; an exhaust fan which is provided in an exhaust duct connected to the outside and receives an air stream blown by the first suction fan in the direction on the opposite side to the conveyance path; a sensor part which measures at least one of the temperature and humidity and outputs a measurement signal indicating a measurement result; and a control unit which controls driving of the heater, the first suction fan and the exhaust fan. The control unit drives the heater and the first suction fan and stops the exhaust fan when the measurement result satisfies a prescribed dew condensation generation condition.SELECTED DRAWING: Figure 7

Description

The present disclosure relates to an image forming apparatus.

Patent Document 1 discloses that in order to prevent dew condensation slip caused by water vapor generated during the process of heating and fixing a recording material with a pressure roller including a heater and condensing on the surface of the pressure roller, a pressure roller is used. An image forming apparatus is disclosed that is provided with a blower fan that blows air to. According to Patent Document 1, when the relative humidity exceeds 30%, the sending fan is rotated and air is blown from the sending fan to the pressure roller to eliminate condensation slip caused by dew condensation on the surface of the pressure roller. It is believed that it can be prevented.

JP2014-38315A

When paper containing a relatively large amount of moisture is heated by a heating roller that includes a heater, water vapor is generated. When the paper heated by the heating roller is conveyed to the conveyance path downstream of the heating roller, the water vapor generated by the heating by the heating roller is transferred to the conveyance path downstream of the heating roller. condensation may form on the surface of the Particularly in winter, when the temperature is low, dew condensation tends to adhere to the surface of the conveyance path on the downstream side of the heating roller, where the temperature is lower than that of the heating roller including the heater. Even if air is blown from a fan to the pressure roller as in the image forming apparatus according to Patent Document 1, it is insufficient to prevent dew condensation on the surface of the conveyance path where the temperature is low. An object of the present disclosure is to provide an image forming apparatus that suppresses dew condensation from adhering to a conveyance path downstream of a heating roller.

An image forming apparatus according to an aspect of the present disclosure includes a heating roller including a heater, a pressure roller for pressurizing a sheet of paper against the heating roller and ejecting the sheet, and ejecting the sheet from the heating roller and the pressure roller. A first intake fan is provided in such a manner that the conveyance path is interposed between a conveyance path through which the paper is conveyed and the heating roller, and a first intake fan is provided in an exhaust duct connected to the outside and connected to the conveyance path. an exhaust fan that receives the airflow blown by the first intake fan in the opposite direction; a sensor unit that measures at least one of temperature and humidity and outputs a measurement signal indicating the measurement result; the heater; a control unit that controls driving of the first intake fan and the exhaust fan; the control unit drives the heater and the first intake fan when the measurement result satisfies a predetermined condensation generation condition; Stop the exhaust fan.

According to the image forming apparatus according to one aspect of the present disclosure, it is possible to suppress dew condensation on the conveyance path downstream of the heating roller.

FIG. 1 is a sectional view showing the configuration of an image forming apparatus according to an embodiment. FIG. 2 is a perspective view of the fixing device and the heat radiation mechanism according to the embodiment, viewed from the side wall outside the exhaust duct. FIG. 3 is a perspective view of the fixing device and the heat radiation mechanism according to the embodiment, viewed from the inner side side of the exhaust duct. FIG. 4 is a perspective view showing a cross section of the exhaust duct according to the embodiment taken in the extending direction. FIG. 5 is a functional block diagram showing a schematic configuration of an image forming apparatus according to an embodiment. FIG. 3 is a diagram illustrating how the image forming apparatus radiates heat from a heater to the outside of the image forming apparatus according to the embodiment. FIG. 7 is a diagram illustrating airflow when the image forming apparatus according to the embodiment operates in the dew condensation suppression mode. FIG. 8 is a diagram showing the flow of operations of the image forming apparatus according to the embodiment. FIG. 9 is a diagram showing the flow of airflow when the first exhaust shutter and the second exhaust shutter are in the closed state in the image forming apparatus according to the first modification of the embodiment. FIG. 10 is a diagram illustrating the flow of airflow when the first exhaust shutter and the second exhaust shutter are in the open state in the image forming apparatus according to the first modification of the embodiment. FIG. 11 is a diagram showing the flow of airflow when the back conveyance path shutter is in the closed state in the image forming apparatus according to the second modification of the embodiment. FIG. 12 is a diagram illustrating the flow of airflow when the back conveyance path shutter is in an open state in the image forming apparatus according to Modification 2 of the embodiment. FIG. 13 is a diagram illustrating the flow of airflow when the first exhaust shutter, the second exhaust shutter, and the back conveyance path shutter are in the closed state in the image forming apparatus according to the third modification of the embodiment. FIG. 14 is a diagram showing the flow of airflow when the first exhaust shutter and the second exhaust shutter are in the closed state and the back conveyance path shutter is in the open state in the image forming apparatus according to the third modification of the embodiment. . FIG. 15 shows airflow when the first intake fan rotates in the forward direction, the second intake fan rotates in the opposite direction, and the back conveyance path shutter is in the closed state in the image forming apparatus according to Modification 4 of the embodiment. It is a diagram showing the flow. FIG. 16 shows airflow when the first intake fan rotates in the forward direction, the second intake fan rotates in the opposite direction, and the back conveyance path shutter is in the open state in the image forming apparatus according to the fourth modification of the embodiment. It is a diagram showing the flow.

[Embodiment]
This embodiment will be described below with reference to the drawings. In the drawings, the same or equivalent elements are denoted by the same reference numerals, and redundant description will be omitted. Note that this embodiment described below does not unduly limit the content described in the claims. Furthermore, not all of the configurations described in this embodiment are essential configuration requirements of the present disclosure.

FIG. 1 is a cross-sectional view showing the configuration of an image forming apparatus 100 according to an embodiment. For example, the image forming apparatus 100 is an apparatus that has an image forming function that forms a color image or a monochrome image, and a printing function that prints the formed image. The image forming apparatus 100 may be a printer, a printer with a scanner function, or a multifunction peripheral (MFP) having various functions including an image forming function and a printing function. good. In this embodiment, as an example, the image forming apparatus 100 will be described as a multifunctional device. For example, the image forming apparatus 100 has a printing function of forming a color image or a monochrome image and printing the formed color image or monochrome image on paper. The types of colors used when the image forming apparatus 100 prints a color image are not limited, but include, for example, black (Bk), cyan (Cy), magenta (Mg), and yellow (Ye). can be mentioned. Further, the image forming apparatus 100 prints a monochrome image on paper using, for example, a single color (for example, black).

For example, the image forming apparatus 100 includes an apparatus main body 101 and an apparatus lid 102 that is attached to the apparatus main body 101 so as to be openable and closable. For example, the device lid portion 102 includes a conveyance path 102a for conveying a document. For example, the apparatus main body 101 includes an image reading device 110, a feeding tray 120 in which paper on which an image is formed (printed) is stored, a plurality of transport rollers, an optical scanning device 160, and image forming stations Pa and Pb. - Pc and Pd, an intermediate transfer belt 151, a belt cleaning device 152, a transfer device 153, a fixing device 10, and a discharge tray 170. Furthermore, the device main body 101 includes an air passage 21, an exhaust duct 22, a first intake fan 31, a second intake fan 32, a first exhaust fan (exhaust fan) 35, and a second exhaust fan (exhaust fan). 36, an exhaust fan 38, a sensor unit 40, a conveyance path 91 downstream of the fixing device 10, and a back conveyance path 92. Further, although not shown, the apparatus main body 101 includes an operation section that is an input interface that receives input operations from the user.

The plurality of conveyance rollers are a paper conveyance mechanism for conveying the paper on which an image is formed, and include, for example, a pickup roller 131, a conveyance roller 132, a registration roller 133, and a discharge roller 134. The optical scanning device 160 and the image forming stations Pa, Pb, Pc, and Pd are image forming mechanisms that form toner images (images for printing) that are transferred to paper. The intermediate transfer belt 151, the belt cleaning device 152, the transfer device 153, and the fixing device 10 are printing mechanisms that transfer (print) the toner image (image for printing) formed by the image forming mechanism onto paper. . The air passage 21, the exhaust duct 22, the first intake fan 31, the second intake fan 32, the first exhaust fan 35, the second exhaust fan 36, the exhaust fan 38, and the sensor section 40 are: This is a heat radiation mechanism 200 for radiating heat from the fixing device 10 to the outside of the image forming apparatus 100. Note that details of the heat dissipation mechanism 200 will be described later using drawings after FIG. 2 as well.

The image reading device 110 reads an image on a document mounted on the image reading device 110, and stores image data representing the read image in the storage unit 70 (FIG. 5). The document to be read by the image reading device 110 may be conveyed by the transport path 102a and read by the image reading device 110, or the document may be directly placed on the image reading device 110 and read by the user. The feed tray 120 stores paper before printing. The feeding tray 120 is, for example, provided in the apparatus main body 101 so as to be able to be pulled out.

The image forming stations Pa, Pb, Pc, and Pd intermediately transfer toner images (images) onto the surface of the intermediate transfer belt 151. Image forming stations Pa, Pb, Pc, and Pd are provided for each type of color used when the image forming apparatus 100 prints an image. For example, the image forming station Pa intermediately transfers a yellow toner image onto the intermediate transfer belt 151, the image forming station Pb intermediately transfers a magenta toner image onto the intermediate transfer belt 151, and the image forming station Pc intermediately transfers a yellow toner image onto the intermediate transfer belt 151. The image is intermediately transferred onto the intermediate transfer belt 151, and the image forming station Pd intermediately transfers the black toner image onto the intermediate transfer belt 151. Note that when the image forming apparatus 100 prints only monochrome images instead of color images, only one of the image forming stations Pa, Pb, Pc, and Pd may be provided.

The image forming stations Pa, Pb, Pc, and Pd each include a developing device 141, a photosensitive drum 142, a drum cleaning device 143, a charger 144, and the like. Toner images are formed in each of the image forming stations Pa, Pb, Pc, and Pd in the following manner. A drum cleaning device 143 removes and collects residual toner on the surface of the photoreceptor drum 142. Thereafter, the surface of the photoreceptor drum 142 is uniformly charged to a predetermined potential by the charger 144. Then, the charged surface of the photoreceptor drum 142 is exposed to light from the optical scanning device 160, and an electrostatic latent image is formed on the surface of the photoreceptor drum 142. Thereafter, the developing device 141 supplies toner to the electrostatic latent image formed on the surface of the photoreceptor drum 142, and the image is visualized (developed). As a result, a toner image of each color is formed on each photoreceptor drum 142 provided in each of the image forming stations Pa, Pb, Pc, and Pd.

The intermediate transfer belt 151 is provided so as to be in contact with the surface of each photoreceptor drum 142 provided in each of the image forming stations Pa, Pb, Pc, and Pd. Intermediate transfer belt 151 rotates in the direction of arrow C. As a result, the toner images of each color formed on the surface of each photoreceptor drum 142 provided in each of the image forming stations Pa, Pb, Pc, and Pd are transferred to the surface of the intermediate transfer belt 151. Intermediate transfer is performed sequentially. In this way, a color toner image is formed on the surface of the intermediate transfer belt 151. Then, the toner image formed on the surface of the intermediate transfer belt 151 is transferred onto the surface of the paper sheet fed one by one from the feeding tray 120 at a position corresponding to the transfer device 153.

Belt cleaning device 152 cleans the surface of intermediate transfer belt 151. The belt cleaning device 152 comes into contact with the surface of the intermediate transfer belt 151 at a position downstream of the position where the toner image on the intermediate transfer belt 151 is transferred to the paper in the direction of arrow C in which the intermediate transfer belt 151 rotates. It is arranged like this. Thereby, the belt cleaning device 152 removes and collects the residual toner on the surface of the intermediate transfer belt 151.

The transfer device 153 includes a transfer roller 153a. The transfer roller 153a is provided facing the surface of the intermediate transfer belt 151 so that a nip area is formed between the transfer roller 153a and the intermediate transfer belt 151. The unprinted paper that has been conveyed to the nip area through the approximately S-shaped paper conveyance path R1 (the sheet conveyance path from the feed tray 120 to the fixing device 10) is transferred to the transfer roller 153a. The toner image formed on the surface of the intermediate transfer belt 151 is transferred while being sandwiched and conveyed in the nip area between the intermediate transfer belt 151 and the intermediate transfer belt 151 . Thereafter, the paper on which the toner image has been transferred, which has passed through the nip area between the transfer roller 153a and the intermediate transfer belt 151, is conveyed to the fixing device 10.

The fixing device 10 includes a heating roller 11 and a pressure roller 12. The heating roller 11 has a heater 11a provided inside. The paper onto which the toner image has been transferred in the nip area is sandwiched between the heating roller 11 and the pressure roller 12. As a result, the heating roller 11 driven by the heater 11a heats the paper, and the pressure roller 12 presses the paper against the heating roller 11 while ejecting the paper. As a result, the toner image transferred to the paper is fixed. That is, printing of an image or the like on one side (for example, the front side) of both sides of the paper is completed.

The paper conveyance path R1 includes a plurality of rollers, such as a pickup roller 131, a conveyance roller 132, a registration roller 133, the above-mentioned intermediate transfer belt 151 and transfer roller 153a, and the above-mentioned heating roller 11 in the fixing device 10. and pressure roller 12 are provided in this order.

A discharge roller 134 is provided between the fixing device 10 and the discharge tray 170 on the paper conveyance path R2 on the downstream side of the fixing device 10 . Paper transport path R2 is a path from fixing device 10 to discharge tray 170. A conveyance path 91 is provided along the paper conveyance path R2, through which the sheet discharged from the heating roller 11 and the pressure roller 12 is conveyed. The conveyance path 91 extends downstream of the fixing device 10 so as to extend from the fixing device 10 to the discharge tray 170 .

A plurality of rollers are also provided on the paper transport path R3, which is downstream from the fixing device 10 and is a path through which the paper passes when printing on the back side of the paper. The paper conveyance path R3 is a path from the conveyance path 91 to the registration rollers 133. A back surface conveyance path 92 is provided along the paper conveyance path R3, through which the sheet discharged from the heating roller 11 and the pressure roller 12 to the conveyance path 91 is conveyed. The back surface conveyance path 92 is adjacent to the conveyance path 91 and extends downstream of the fixing device 10 so as to extend in a direction away from the conveyance path 91 and toward the registration rollers 133 .

The pickup roller 131 is provided so as to come into contact with the paper stored in the feed tray 120, and is a roller located closest to the feed tray 120 (furthest from the output tray 170) among the plurality of rollers. be. The discharge roller 134 is provided adjacent to the discharge tray 170, and is the roller located closest to the discharge tray 170 (furthest from the feed tray 120) among the plurality of rollers. A plurality of unprinted sheets stored in the feed tray 120 are pulled out from the feed tray 120 one by one by a pickup roller 131, and are moved along the paper conveyance path R1 by a conveyance roller 132 and a registration roller 133. Then, the image is transported to the fixing device 10.

The conveyance roller 132 urges the sheet to be conveyed from the pickup roller 131 to the registration roller 133. The registration roller 133 is provided at an upstream position immediately before the intermediate transfer belt 151 and the transfer roller 153a, where the toner image is transferred to the paper, in the paper conveyance path R1. Then, the registration rollers 133 once stop the paper and align the leading edges of the paper before conveying the paper to the intermediate transfer belt 151 and the transfer roller 153a. After the registration rollers 133 temporarily stop the paper, they transport the paper in accordance with the timing of transferring the toner image in the nip area between the intermediate transfer belt 151 and the transfer roller 153a.

The paper discharged from the registration roller 133 passes between the intermediate transfer belt 151 and the transfer roller 153a, and between the heating roller 11 and the pressure roller 12, so that an image or the like is formed on one side of both surfaces. is printed. If the printing on the paper is only on one side, the paper is conveyed from the heating roller 11 and the pressure roller 12 onto the conveyance path 91 along the paper conveyance path R2 and is ejected via the ejection roller 134. It is discharged onto the tray 170.

When printing on both sides of paper, the paper printed on one side is first discharged from the heating roller 11 and pressure roller 12 onto the conveyance path 91 on the downstream side of the fixing device 10, and then the discharge roller 134 reverses the paper. By rotating or the like, the sheet is conveyed from the conveyance path 91 onto the back surface conveyance path 92 adjacent to the conveyance path 91, and then conveyed to the registration rollers 133 along the paper conveyance path R3, with the front and back sides reversed. Then, the paper discharged from the registration roller 133 again passes between the intermediate transfer belt 151 and the transfer roller 153a, and between the heating roller 11 and the pressure roller 12, so that an image or the like is printed on the back side. Ru. In this way, images and the like are printed on both sides of the paper. Then, the paper with the image etc. printed on the back side is transported from the heating roller 11 and the pressure roller 12 onto the transport path 91 along the paper transport path R2, and is ejected to the ejection tray 170 via the ejection roller 134. be done.

Next, an example of the configuration of the heat dissipation mechanism 200 will be described using FIGS. 1 to 4. FIG. 2 is a perspective view of the fixing device 10 and the heat radiation mechanism 200 viewed from the outer side wall of the exhaust duct 22, according to the embodiment. FIG. 3 is a perspective view of the fixing device 10 and the heat radiation mechanism 200 viewed from the inner side side of the exhaust duct 22, according to the embodiment. FIG. 4 is a perspective view showing a cross section of the exhaust duct 22 according to the embodiment taken in the extending direction. Note that in FIGS. 2 and 3, the fixing device 10 is shown in a cross section taken in a direction perpendicular to the stretching direction of the heating roller 11 and the pressure roller 12. The heat dissipation mechanism 200 includes, for example, the above-mentioned air passage 21, exhaust duct 22, first intake fan 31, second intake fan 32, first exhaust fan 35, second exhaust fan 36, and exhaust port fan 38 (see FIG. 1). ), a sensor section 40 (see FIG. 1), and an exhaust filter 37 (see FIG. 4). Note that the heat radiation mechanism 200 may have a configuration in which the exhaust port fan 38 is omitted.

As shown in FIGS. 1 to 3, a heater 11a that generates heat is provided inside the heating roller 11. As shown in FIGS. The conveyance path 91 on the downstream side of the fixing device 10 is adjacent to the heating roller 11 and the pressure roller 12 , and is curved above the heating roller 11 and extends to the discharge roller 134 .

The air passage 21 is an air flow passage for guiding the heat generated by the heater 11a to the exhaust duct 22. For example, the ventilation path 21 is provided above the conveyance path 91 and below the support member 180 that supports the image reading device 110. For example, the ventilation path 21 is arranged above the conveyance path 91 and the back surface conveyance path 92 (see FIG. 1), and overlaps with each.

When driven, the first intake fan 31 and the second intake fan 32 generate an airflow 5 (see FIG. 4) for guiding heat from the heater 11a to the exhaust duct 22 via the air passage 21. The first intake fan 31 and the second intake fan 32 are provided so that a conveyance path 91 is interposed between them and the heating roller 11 . The first intake fan 31 and the second intake fan 32 are arranged, for example, at the bottom of the air passage 21 so as to face the conveyance passage 91. The first intake fan 31 and the second intake fan 32 are arranged side by side along the direction in which the discharge roller 134 extends. Note that in this embodiment, the image forming apparatus 100 will be described as including two first intake fans 31 and second intake fans 32; however, the number of intake fans included in the image forming apparatus 100 is not limited to two. , or may be one or more.

The exhaust duct 22 is arranged beside the air passage 21 so as to be in contact with the air passage 21. The exhaust duct 22 extends along the direction in which the heating roller 11 extends. The exhaust duct 22 extends along the direction in which the first intake fan 31 and the second intake fan 32 are lined up, and is connected to the outside of the image forming apparatus 100 . The exhaust duct 22 includes exhaust fan accommodating parts 22A1 and 22A2 provided adjacent to the air passage 21, and a downstream side of the exhaust fan accommodating parts 22A1 and 22A2 (a side closer to the exhaust port leading to the outside of the image forming apparatus 100). ) is provided with an exhaust filter housing portion 22A3.

As shown in FIG. 4, within the exhaust duct 22, a first exhaust fan 35 is provided within the exhaust fan housing section 22A1, a second exhaust fan 36 is provided within the exhaust fan housing section 22A2, and an exhaust filter housing section 22A1 is provided with a first exhaust fan 35. An exhaust filter 37 is provided within the portion 22A3. Furthermore, an exhaust fan 38 (see FIGS. 1 and 6) is provided in the exhaust duct 22 on the downstream side of the exhaust filter 37 (on the side closer to the exhaust port leading to the outside of the image forming apparatus 100). . An opening H2a and an opening H2b are formed in the inner side wall of the exhaust duct 22 that contacts the air passage 21, through which the airflow 5 blown from the air passage 21 passes. The opening H2a is formed to face the first exhaust fan 35. The opening H2b is formed to face the second exhaust fan 36.

The first exhaust fan 35 and the second exhaust fan 36 receive the airflow 5 blown in the direction opposite to the conveyance path 91 by the first intake fan 31 and the second intake fan 32, and are operated on the downstream side of the exhaust duct 22. flow to When the first exhaust fan 35 is driven, it receives the airflow 5a that has been blown from the airflow path 21 through the opening H2a, out of the airflow 5 that has been blown by the first intake fan 31 and the second intake fan 32. , and further blows air to the downstream side of the exhaust duct 22. When driven, the second exhaust fan 36 receives the airflow 5b blown from the airflow passage 21 through the opening H2b, out of the airflow 5 blown by the first intake fan 31 and the second intake fan 32. , the air is blown to the downstream side of the exhaust duct 22.

FIG. 5 is a functional block diagram showing a schematic configuration of the image forming apparatus 100 according to the embodiment. Image forming apparatus 100 includes a sensor section 40, a control section 60, a storage section 70, and a communication section 80.

The sensor unit 40 is provided within the image forming apparatus 100, for example. The sensor unit 40 measures at least one of temperature and humidity, and outputs a measurement signal indicating the measurement result. Specifically, the sensor unit 40 is a temperature sensor that measures temperature and outputs a measurement signal indicating the measured temperature as the measurement result, or a temperature sensor that measures temperature and humidity and outputs the measured temperature and measured humidity as the measurement results. This is a temperature/humidity sensor that outputs a measurement signal indicating . Note that the sensor section 40 may have a structure that can measure the temperature of the air, or may have a structure that can measure the surface temperature of the conveyance path 91.

The control unit 60 controls the driving of each unit included in the image forming apparatus 100. The control unit 60 includes a processor such as a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), a DSP (Digital Signal Processor), and an ASIC (application specific integrated circuit). For example, the control unit 60 reads and executes a computer-readable control program stored in the storage unit 70, thereby controlling the image reading device 110, the plurality of transport rollers, the optical scanning device 160, the image forming station Pa, Pb/Pc/Pd, intermediate transfer belt 151, belt cleaning device 152, transfer device 153, storage section 70, communication section 80, heating roller 11, heater 11a, pressure roller 12, first intake fan 31, second intake fan 32, controls the driving of each of the first exhaust fan 35, the second exhaust fan 36, the exhaust port fan 38, and the sensor section 40. Further, although the details will be described later, if the measurement result indicated by the measurement signal output by the sensor unit 40 satisfies a predetermined condensation generation condition, the control unit 60 controls the heater 11a, the first intake fan 31, and the second intake fan 31. The fan 32 is driven, and the first exhaust fan 35, second exhaust fan 36, and exhaust port fan 38 are stopped.

The storage unit 70 is a computer-readable recording medium. The storage unit 70 may be a semiconductor memory such as an SRAM (Static Random Access Memory), a DRAM (Dynamic Random Access Memory), a ROM (Read Only Memory), or a flash memory, a register, or a hard disk. It may be a magnetic storage device such as a hard disk drive (HDD), or an optical storage device such as an optical disk device. The storage unit 70 non-temporarily stores a control program (not shown). The control program stored in the storage unit 70 may be stored in the storage unit 70 in advance, or may be supplied to the storage unit 70 via a wide area communication network including the Internet.

The communication unit 80 is an interface for communicating with external devices. The communication unit 80 may include, for example, a FAX modem, an interface that performs communication according to the USB standard, or an interface that performs communication according to the IEEE802.11 method. However, it may be an interface that performs communication according to other methods.

FIG. 6 is a diagram showing how the image forming apparatus 100 radiates heat from the heater 11a to the outside of the image forming apparatus 100, according to the embodiment. In FIG. 6, the heat radiation mechanism 200, the heating roller 11, the pressure roller 12, the downstream conveyance path 91 of the heating roller 11 and the pressure roller 12, and the back surface conveyance path 92 are each schematically illustrated.

Inside the exhaust duct 22, a first exhaust fan 35, a second exhaust fan 36, an exhaust filter 37, and an exhaust port fan 38 are arranged in order from the upstream side to the downstream side. The end of the exhaust duct 22 facing the exhaust port fan 38 is an exhaust port 22e that connects to the outside of the image forming apparatus 100. Further, a structure that becomes a wall that partitions the exhaust duct 22 and the air passage 21 (for example, a structure that includes the inner side surface of the exhaust duct 22) is referred to as a wall W1. An opening H2a is formed in the wall W1 to face the first exhaust fan 35, and an opening H2b is formed to face the second exhaust fan 36.

The ventilation path 21 is provided, for example, so as to face the conveyance path 91 and the back surface conveyance path 92. A structure that serves as a wall that partitions the inside of the ventilation path 21 and the conveyance path 91 (for example, a structure that includes the bottom of the ventilation path 21) is referred to as a wall W2. The wall W2 is provided to face the conveyance path 91. The first intake fan 31 and the second intake fan 32 are provided on the wall W2, and each faces the conveyance path 91. For example, an opening H1 is formed in the wall W2 so as to face the conveyance path 91. Further, the wall W2 also faces the back conveyance path 92. For example, an opening H3 is formed in the wall W2 so as to face the back conveyance path 92.

Before starting printing, the control unit 60 drives the heater 11a to generate heat. As a result, the heat from the heater 11a is transmitted to the surface of the heating roller 11, and the surface of the heating roller 11 is heated. The control unit 60 also controls the first intake fan 31 and the second intake fan 31 to radiate heat from the heater 11a, which is emitted into the image forming apparatus 100 via the heating roller 11, to the outside of the image forming apparatus 100. The fan 32, the first exhaust fan 35, the second exhaust fan 36, and the exhaust port fan 38 are driven to rotate in the forward direction. The rotation of the first intake fan 31 and the second intake fan 32 in the positive direction means that each of the first intake fan 31 and the second intake fan 32 rotates from the conveyance path 91 to the side opposite to the conveyance path 91. It is a rotation that blows air in the direction. Further, the rotation of the first exhaust fan 35, the second exhaust fan 36, and the exhaust port fan 38 in the positive direction means that each of the first exhaust fan 35, the second exhaust fan 36, and the exhaust port fan 38 This is a rotation that blows air from the upstream to the downstream direction in the duct 22 (the direction toward the exhaust port 22e).

The airflow 5a generated by the rotation of the first intake fan 31 in the forward direction contains the heat from the heater 11a transmitted to the surface of the heating roller 11, passes through the surface of the conveyance path 91, and passes through the first intake fan 31. The air flows into the air passage 21, and most of it hits the first exhaust fan 35. Furthermore, the airflow 5b generated by the rotation of the second intake fan 32 in the forward direction contains the heat from the heater 11a transmitted to the surface of the heating roller 11, passes through the surface of the conveyance path 91, and passes through the second intake fan 32. It reaches the inside of the air passage 21 through the air, and most of it hits the second exhaust fan 36.

As the first exhaust fan 35 rotates in the forward direction, the airflow 5a taken into the air passage 21 by the first intake fan 31 passes through the opening H2a and the first exhaust fan 35, and passes through the opening H2a and the first exhaust fan 35 to the downstream side of the exhaust duct 22. Air is blown to. In addition, as the second exhaust fan 36 rotates in the forward direction, the airflow 5b taken into the air passage 21 by the second intake fan 32 passes through the opening H2b and the second exhaust fan 36, and the airflow 5b flows through the exhaust duct 22. Air is blown downstream. As the exhaust fan 38 rotates in the forward direction, the airflows 5a and 5b blown to the downstream side of the exhaust duct 22 by the first exhaust fan 35 and the second exhaust fan 36 are transferred to the exhaust filter 37 and the exhaust fan 37. 38 and is discharged to the outside of the image forming apparatus 100 from the exhaust port 22e, which is the end of the exhaust duct 22. Thereby, the image forming apparatus 100 can radiate the heat from the heater 11a transmitted to the surface of the heating roller 11 to the outside of the image forming apparatus 100. Thereby, the image forming apparatus 100 can suppress heat from the heater 11a from being trapped inside the image forming apparatus 100 when printing on paper.

Here, when printing on paper, if the paper containing a lot of water is heated by the heating roller 11, water vapor may be generated. Then, when the paper heated by the heating roller 11 is transported onto the transport path 91 located downstream of the heating roller 11 and the pressure roller 12, the heating roller 11 heats the paper as the paper is transported. The water vapor generated as a result of this may adhere as dew on the conveyance path 91 located on the downstream side where the temperature is lower than that of the heating roller 11. If dew condensation adheres on the conveyance path 91, the paper conveyed to the conveyance path 91 will become wet, causing wrinkles to form on the paper, toner images not being properly transferred to the paper, and problems with the paper being conveyed to the downstream side of the conveyance path 91. Problems such as paper jams may occur due to insufficient conveyance.

As described above, during printing, the control unit 60 rotates each of the first intake fan 31, second intake fan 32, first exhaust fan 35, second exhaust fan 36, and exhaust port fan 38 in the forward direction. to generate airflow 5. As a result, the airflow 5 contains not only the heat from the heating roller 11 but also water vapor generated by the heating of the paper by the heating roller 11, and passes through the surface of the conveying path 91 and exits the image forming apparatus 100 via the exhaust duct 22. is exhausted to. As a result, it is possible to suppress, to some extent, the water vapor generated by the heating of the sheet by the heating roller 11 from adhering to the conveyance path 91 on the downstream side of the heating roller 11 as dew condensation. However, depending on the temperature and humidity inside the image forming apparatus 110, dew condensation may easily form on the surface of the conveyance path 91 on the downstream side of the heating roller 11. This may be due to the following reasons.

For example, when the temperature is low such as winter, the amount of saturated water vapor that can be contained in the air is smaller than when the temperature is high. Even if water vapor is generated, dew condensation is likely to occur on the surface of the conveyance path 91.

Furthermore, since the air near the heating roller 11 has a high temperature and a large amount of saturated water vapor, the water vapor generated by heating the paper by the heating roller 11 remains in the form of gaseous water vapor near the heating roller 11. I can do it. However, when the air near the heating roller 11 comes into contact with the surface of the conveyance path 91 whose temperature is lower than that of the heating roller 11, it is cooled and the saturated water vapor amount becomes small, and the water vapor contained in the air is transferred to the conveyance path 91. Condensation tends to form on the surface.

Further, if the humidity inside the image forming apparatus 110 is high, even if the amount of water vapor generated by heating the paper by the heating roller 11 is small, it will easily reach the saturated amount of water vapor, and the surface of the conveyance path 91 will be prone to dew condensation. Furthermore, when the humidity inside the image forming apparatus 110 is high, the moisture content of the paper itself increases, and the amount of water vapor generated by heating the paper by the heating roller 11 also increases, causing dew condensation on the surface of the conveyance path 91. It becomes easier.

In this way, by rotating each of the first intake fan 31, the second intake fan 32, the first exhaust fan 35, the second exhaust fan 36, and the exhaust port fan 38 in the forward direction, water vapor is imaged together with the airflow 5 generated. Merely discharging to the outside of the forming apparatus 100 may not be sufficient to prevent dew condensation from adhering to the surface of the conveyance path 91 where the temperature is low.

Therefore, when the image forming apparatus 100 according to the present embodiment determines that a predetermined dew condensation generation condition, which is a condition in which dew condensation is likely to occur, is satisfied before printing, the image forming apparatus 100 suppresses dew condensation from adhering to the conveyance path 91. Operates according to mode. Next, the operation in the dew condensation suppression mode in the image forming apparatus 100 will be described using FIG. 7.

FIG. 7 is a diagram showing the flow of the airflow 6 when the image forming apparatus 100 according to the embodiment operates in the dew condensation suppression mode. For example, when the control unit 60 obtains a print instruction that is an instruction signal to start printing, the control unit 60 detects at least one of temperature and humidity from the sensor unit 40 (FIGS. 1 and 5) before starting printing. Obtain a measurement signal indicating the measured measurement result. Then, the control unit 60 determines whether the measurement result indicated by the measurement signal acquired from the sensor unit 40 satisfies a predetermined condensation generation condition.

The predetermined condensation generation condition is, for example, when the temperature is less than a predetermined temperature threshold, or when the humidity is greater than or equal to a predetermined humidity threshold. If the predetermined dew condensation conditions are met, the control unit 60 can determine that the environment is such that dew condensation easily adheres to the surface of the conveyance path 91, and therefore performs the operation in the dew condensation suppression mode. Thereby, as will be described later, it is possible to suppress dew condensation from adhering to the surface of the conveyance path 91. Note that the temperature measured by the sensor section 40 in order for the control section 60 to determine whether or not the predetermined condensation generation condition is satisfied may be the temperature of the air or the surface temperature of the conveyance path 91. good.

Specifically, when a predetermined condensation condition is satisfied, the control unit 60 drives the heater 11a to generate heat, rotates each of the first intake fan 31 and the second intake fan 32 in the forward direction, and The exhaust fan 35, second exhaust fan 36, and exhaust port fan 38 are stopped.

The airflow 6a generated by the rotation of the first intake fan 31 in the forward direction is warm air containing heat from the heater 11a that has been transmitted to the surface of the heating roller 11, and the airflow 6a is warm air containing heat from the heater 11a that has been transmitted to the surface of the heating roller 11. The air flows along the surface of the air, reaches into the air passage 21 via the first intake fan 31, and most of the air hits the first exhaust fan 35 and the wall W1. However, since the first exhaust fan 35 does not rotate and is stopped, it acts as a resistance to the airflow 6a, and the airflow 6a that hits the first exhaust fan 35 and the wall W1 rebounds and moves toward the wall W2. The airflow 6a then passes through the opening H1 formed in the wall W2 and hits the surface of the conveyance path 91. As a result, the temperature of the surface of the conveyance path 91 becomes more likely to rise.

Furthermore, the airflow 6b generated by the rotation of the second intake fan 32 in the forward direction is warm air containing heat from the heater 11a transmitted to the surface of the heating roller 11, and is transported while warming the surface of the transport path 91. It travels along the surface of the path 91 and reaches the inside of the air blowing path 21 via the second intake fan 32, and most of it hits the second exhaust fan 36 and the wall W1. However, since the second exhaust fan 36 does not rotate and is stopped, it acts as a resistance to the airflow 6b, and the airflow 6b that hits the second exhaust fan 36 and the wall W1 rebounds and moves toward the wall W2. The airflow 6b then passes through the opening H1 formed in the wall W2 and hits the surface of the conveyance path 91. As a result, the temperature of the surface of the conveyance path 91 becomes more likely to rise.

In this way, before starting printing, the temperature of the surface of the conveyance path 91 can be raised in a relatively short period of time to make it difficult for dew condensation to adhere to the surface of the conveyance path 91. That is, it is possible to suppress dew condensation from adhering to the surface of the conveyance path 91.

Further, the airflow 6c, which is a part of the airflow 6 blown by the first intake fan 31 and the second intake fan 32 and hits the first exhaust fan 35, the second exhaust fan 36, and the wall W1, is inside the air passage 21. , it advances to the wall W2 near the back surface conveyance path 92, passes through an opening H3 formed in the wall W2, and hits the front surface of the back surface conveyance path 92. As a result, the temperature of the surface of the back conveyance path 92 tends to rise, and the surface of the back conveyance path 92 can be made in a state where dew condensation is difficult to adhere to. That is, it is possible to suppress dew condensation from adhering to the surface of the back conveyance path 92.

FIG. 8 is a diagram showing the flow of operations of the image forming apparatus 100 according to the embodiment. In step S11, the control unit 60 determines whether there is a print instruction, which is an instruction signal to start printing, based on input from the user or the like. In step S11, if there is no print instruction (No in step S11), the control unit 60 continues the process of step S11. If there is a print instruction in step S11 (in the case of Yes in step S11), then in step S12, the control unit 60 sends a measurement signal indicating the measurement result of at least one of temperature and humidity measured by the sensor unit 40. is acquired, and it is determined whether the measurement result indicated by the acquired measurement signal satisfies a predetermined condensation generation condition.

In step S12, the control unit 60 determines whether the measurement result obtained from the sensor unit 40 satisfies a predetermined condensation generation condition. In step S12, if the control unit 60 determines that the measurement result obtained from the sensor unit 40 does not satisfy the predetermined dew condensation generation condition (in the case of No in step S12), the control unit 60 provides an environment in which dew condensation is difficult to adhere to the surface of the conveyance path 91. Since it can be determined that this is the case, the process proceeds to step S15, which will be described later.

In step S12, if the control unit 60 determines that the measurement result obtained from the sensor unit 40 satisfies the predetermined dew condensation generation condition (in the case of Yes in step S12), the control unit 60 determines that the surface of the conveyance path 91 is in an environment where dew condensation is likely to adhere. Since it can be determined that there is a dew condensation suppression mode, the control unit 60 then executes an operation in the dew condensation suppression mode in step S13.

That is, in step S13, the control unit 60 causes the heater 11a to generate heat, drives each of the first intake fan 31 and the second intake fan 32 to rotate in the forward direction, and causes the first exhaust fan 35 to rotate in the forward direction. , the second exhaust fan 36 and the exhaust port fan 38 are stopped. As a result, the airflow 6, which is warm air containing heat from the heater 11a and which is generated when the first intake fan 31 and the second intake fan 32 rotate in the forward direction, is directed to the conveyance path located downstream of the heating roller 11. While warming the conveyance path 91 by moving along the surface of the fan 91 , the air passes through the first intake fan 31 and the second intake fan 32 and reaches the inside of the ventilation path 21 . Then, the first exhaust fan 35 and the second exhaust fan 36, which have stopped rotating, and the wall W2 act as resistance, so that the air bounces back, passes through the opening H1 formed in the wall W2, and returns to the transport path 91. The temperature of the surface of the conveyance path 91 is increased by hitting the surface of the conveyance path 91. Further, the airflow 6c, which is a part of the airflow 6b in the air passage 21, passes through the opening H3 formed in the wall W2 and hits the surface of the back conveyance path 92, thereby increasing the temperature of the surface of the back conveyance path 92. raise.

Next, in step S14, the control unit 60 determines whether a predetermined dew condensation avoidance condition is satisfied. The predetermined condensation avoidance conditions are, for example, (1) when the temperature indicated by the measurement result included in the measurement signal obtained from the sensor section 40 is equal to or higher than a predetermined temperature threshold; (2) when the measurement obtained from the sensor section 40 When the humidity indicated by the measurement result included in the signal is less than a predetermined humidity threshold, or (3) when a predetermined time has elapsed after starting the process of step S13 (execution of operation in dew condensation suppression mode), etc. can be mentioned.

The control unit 60 may determine that a predetermined condensation avoidance condition is satisfied when one or two of the conditions (1) to (3) above are satisfied, or the control unit 60 may determine that the predetermined condensation avoidance condition is satisfied when one or two of the conditions (1) to (3) above are satisfied. If all the conditions are met, it may be determined that the predetermined dew condensation avoidance conditions are met. Note that the temperature measured by the sensor unit 40 may be the temperature of air or the surface temperature of the conveyance path 91. In addition, the predetermined time from the start of the process in step S13 in (3) above is, for example, the time during which it is assumed that dew condensation can be prevented within the environmental specification range determined by a preliminary experiment, or the predetermined time determined by a preliminary experiment. In addition, the time estimated to be required until the current temperature and humidity change to a temperature and humidity that can prevent dew condensation can be mentioned.

In step S14, if the control unit 60 determines that the predetermined dew condensation avoidance condition is not satisfied (No in step S14), it repeats the process of step S14. In step S14, if the control unit 60 determines that the predetermined dew condensation avoidance condition is satisfied (in the case of Yes in step S14), it can be determined that the environment has become such that dew condensation is difficult to adhere to the surface of the conveyance path 91. In step S15, the control unit 60 causes the image forming apparatus 100 to perform operations in the printing and heat dissipation modes.

Specifically, in step S15, the control unit 60 maintains the heating state in which the heater 11a is driven, and the state in which each of the first intake fan 31 and the second intake fan 32 is driven and rotated in the forward direction. is maintained, and each of the first exhaust fan 35, second exhaust fan 36, and exhaust port fan 38 is driven. As a result, each of the first exhaust fan 35, the second exhaust fan 36, and the exhaust port fan 38 rotates in the forward direction.

As a result, the surface of the heating roller 11 is maintained in a heated state due to the heat from the heater 11a, and the heat from the heater 11a generated by the rotation of the first intake fan 31 and the second intake fan 32 in the forward direction is maintained. The airflow 5 containing heat passes through the first intake fan 31 and the second intake fan 32 and reaches the inside of the air passage 21 . Then, as the first exhaust fan 35 and the second exhaust fan 36 rotate in the forward direction, the airflow 5 that has reached the inside of the air passage 21 passes through the first exhaust fan 35 and the second exhaust fan 36 and into the exhaust duct. Reach inside 22. The airflow 5 that has reached the inside of the exhaust duct 22 passes through the inside of the exhaust duct 22, passes through the exhaust filter 37 and the exhaust port fan 38, and is discharged to the outside of the image forming apparatus 100 from the exhaust port 22e. Thereby, it is possible to suppress the heat from the heater 11a from being trapped inside the image forming apparatus 100.

Next, in step S16, the control unit 60 starts printing on paper by driving each unit in the image forming apparatus 100. Then, in step S17, when the printing on the paper is completed, the control unit 60 stops driving each unit in the image forming apparatus 100, and puts the image forming apparatus 100 in a standby state.

As described above, according to the image forming apparatus 100 according to the present embodiment, when the measurement result from the sensor unit 40 satisfies the predetermined dew condensation generation condition, the control unit 60 controls the heater 11a, the first intake fan 31, and the second intake fan The fan 32 is driven, and the first exhaust fan 35 and second exhaust fan 36 are stopped. As a result, the airflow 6, which is warm air containing heat from the heater 11a, generated by driving the first intake fan 31 and the second intake fan 32 passes through the first intake fan 31 and the second intake fan 32. After that, when the airflow 6 stops, it bounces off by hitting the first exhaust fan 35 and the second exhaust fan 36, which act as resistance to the airflow 6, and the wall W2 on which the first intake fan 31 and the second intake fan 32 are provided again. It advances in the direction of , passes through the opening H1 formed in the wall W2, and hits the surface of the conveyance path 91. As a result, the temperature of the surface of the conveyance path 91 can be increased in a relatively short period of time, and the surface of the conveyance path 91 can be brought into a state where dew condensation is difficult to adhere to the surface. In this way, the image forming apparatus 100 suppresses dew condensation from adhering to the conveyance path 91 downstream of the heating roller 11.

In addition, the control unit 60 controls the operating states of the first intake fan 31 , the second intake fan 32 , and the first exhaust fan 31 , which controls operating states such as driving and stopping in order to apply the airflow 6 that is hot air to the surface of the conveyance path 91 . The fan 35 and the second exhaust fan 36 are both used to radiate heat from the heater 11a to the outside of the image forming apparatus 100 when printing on paper. Therefore, according to the image forming apparatus 100, there is no need to provide a separate fan to suppress dew condensation from adhering to the surface of the conveyance path 91 located downstream of the heating roller 11. Therefore, according to the image forming apparatus 100, it is possible to prevent an increase in cost caused by providing a separate fan just for suppressing dew condensation on the surface of the conveyance path 91 located downstream of the heating roller 11. I can do it.

The image forming apparatus 100 also includes an air passage 21 that guides the airflow 6 blown by the first intake fan 31 and the second intake fan 32 to the exhaust duct 22, and a heating roller 11 and a pressurizing roller when printing on the back side of the paper. It has a back conveyance path 92 through which the paper discharged from the rollers 12 to the conveyance path 91 is conveyed. The back surface conveyance path 92 is adjacent to the conveyance path 91 and faces the ventilation path 21 . As a result, the airflow 6, which is warm air containing heat from the heater 11a, generated by driving the first intake fan 31 and the second intake fan 32 passes through the first intake fan 31 and the second intake fan 32. After reaching the inside of the ventilation path 21 and bouncing off the first and second exhaust fans 35 and 36 that are stopped, a part of the airflow 6c advances to the wall W2 facing the back conveyance path 92 in the ventilation path 21, It passes through the opening H3 formed in the wall W2 and hits the front surface of the back conveyance path 92. Therefore, the temperature of the surface of the back surface conveyance path 92 also rises in a relatively short period of time, making it difficult for dew condensation to form. In this way, according to the image forming apparatus 100, it is possible to suppress dew condensation from adhering not only to the conveyance path 91 on the downstream side of the heating roller 11 but also to the back surface conveyance path 92 adjacent to the conveyance path 91.

FIG. 9 is a diagram showing the flow of the airflow 6 when the first exhaust shutter 51 and the second exhaust shutter 52 are in the closed state in the image forming apparatus 100 according to the first modification of the embodiment. FIG. 10 is a diagram showing the flow of the airflow 6 when the first exhaust shutter 51 and the second exhaust shutter 52 are in the open state in the image forming apparatus 100 according to the first modification of the embodiment.

As shown in FIGS. 9 and 10, the image forming apparatus 100 may include a first exhaust shutter (exhaust shutter) 51 and a second exhaust shutter (exhaust shutter) 52 that can be opened and closed. The driving of the first exhaust shutter 51 and the second exhaust shutter 52 is controlled by a control unit 60 (see FIG. 5). That is, the control unit 60 switches each of the first exhaust shutter 51 and the second exhaust shutter 52 between an open state and a closed state.

As shown in FIG. 9, when the first exhaust shutter 51 is in the closed state, the airflow from the first intake fan 31 to the first exhaust fan 35 is connected to the flow path of the airflow 6a blown by the first intake fan 31. Block the flow path 6a. That is, the first exhaust shutter 51 is provided so as to face the first exhaust fan 35 and close the opening H2a when in the closed state. In addition, when the second exhaust shutter 52 is in the closed state, the second exhaust shutter 52 closes the flow path of the air flow 6b from the second intake fan 32 to the second exhaust fan 36 among the flow paths of the air flow 6b blown by the second intake fan 32. block. That is, the second exhaust shutter 52 is provided so as to face the second exhaust fan 36 and close the opening H2b when in the closed state.

As shown in FIG. 10, when the first exhaust shutter 51 is in the open state, the flow path of the airflow 5a from the first intake fan 31 to the first exhaust fan 35 is opened (not blocked). . That is, the first exhaust shutter 51 is provided so as not to face the first exhaust fan 35 and not to block the opening H2a when in the open state. Further, when the second exhaust shutter 52 is in the open state, the flow path of the airflow 5b from the second intake fan 32 to the second exhaust fan 36 is opened (not blocked). That is, the second exhaust shutter 52 is provided so as not to face the second exhaust fan 36 and to not block the opening H2b when in the open state.

If the control unit 60 determines in step S12 shown in FIG. 8 that the measurement result obtained from the sensor unit 40 satisfies the predetermined condensation generation condition (in the case of Yes in step S12), then in step S13, the above-mentioned As described above, the heater 11a is driven to generate heat, the first intake fan 31 and the second intake fan 32 are each driven to rotate in the forward direction, and the first exhaust fan 35, second exhaust fan 36, and In addition to bringing the exhaust port fan 38 into a stopped state, each of the first exhaust shutter 51 and the second exhaust shutter 52 is brought into a closed state (the state shown in FIG. 9).

As a result, the airflow 6, which is warm air containing heat from the heater 11a, generated by driving the first intake fan 31 and the second intake fan 32 passes through the first intake fan 31 and the second intake fan 32. After reaching the inside of the air passage 21, it bounces back by hitting the first exhaust shutter 51 and the second exhaust shutter 52 which are in the closed state. In this way, by closing the first exhaust shutter 51 and the second exhaust shutter 52, it is possible to reduce the amount of airflow 6 leaking from the ventilation path 21 to the exhaust duct 22 during operation in the condensation suppression mode. . Therefore, it is possible to increase the amount of airflow 6 that bounces off the first and second exhaust shutters 51 and 52 in the closed state, and more airflow 6 is transported through the opening H1 formed in the wall W2. can be applied to the surface of the channel 91. Thereby, the temperature of the conveyance path 91 can be further increased in a short time to make it difficult for dew condensation to adhere.

Further, it is also possible to increase the amount of the airflow 6c, which is a part of the airflow 6 that hits the first exhaust shutter 51 and the second exhaust shutter 52 in the closed state and bounces back. Thereby, more airflow 6c can be applied to the front surface of the back conveyance path 92 through the opening H3 formed in the wall W2. Therefore, the temperature of the back surface conveyance path 92 can be increased in a shorter time to make it difficult for dew to form.

Further, if the control unit 60 determines in step S14 shown in FIG. 8 that the predetermined condensation avoidance condition is satisfied (in the case of Yes in step S14), then in step S15, as described above, The driven state of generating heat is maintained, the first intake fan 31 and the second intake fan 32 are each kept rotating in the forward direction, and the first exhaust fan 35, the second exhaust fan 36, and the exhaust In addition to driving each of the mouth fans 38, each of the first exhaust shutter 51 and the second exhaust shutter 52 is opened (the state shown in FIG. 10).

As a result, the airflow 5 containing heat from the heater 11a passes through the first intake fan 31 and the second intake fan 32, reaches the inside of the air passage 21, and further passes through the first exhaust shutter 51 and the second exhaust shutter 51, which are in an open state. Without being blocked by the exhaust shutter 52, the air flows through the openings H2a and H2b, the first exhaust fan 35, and the second exhaust fan 36, through the exhaust duct 22, and from the exhaust port 22e to the outside of the image forming apparatus 100. released. Thereby, it is possible to suppress the heat from the heater 11a from being trapped inside the image forming apparatus 100.

FIG. 11 is a diagram showing the flow of the airflow 6 when the back conveyance path shutter 53 is in the closed state in the image forming apparatus 100 according to the second modification of the embodiment. FIG. 12 is a diagram showing the flow of the airflow 6 when the back conveyance path shutter 53 is in the open state in the image forming apparatus 100 according to the second modification of the embodiment.

As shown in FIGS. 11 and 12, the image forming apparatus 100 may include a back conveyance path shutter 53 that can be opened and closed. The driving of the back conveyance path shutter 53 is controlled by a control section 60 (see FIG. 5). That is, the control unit 60 switches the back conveyance path shutter 53 between an open state and a closed state. Note that in the example shown in FIGS. 11 and 12, the image forming apparatus 100 does not include the first exhaust shutter 51 and the second exhaust shutter 52 shown in FIGS. 9 and 10.

As shown in FIG. 11, when the back conveyance path shutter 53 is in the closed state, the first intake fan 53 is a part of the flow path of the airflow 6 blown by the first intake fan 31 and the second intake fan 32. 31 and the second intake fan 32 to the back conveyance path 92 (see FIG. 12). That is, in the closed state, the back conveyance path shutter 53 closes the opening H3 formed in the wall W2 for reaching the back conveyance path 92 from the inside of the ventilation path 21.

As shown in FIG. 12, when the back conveyance path shutter 53 is in the open state, the flow path of the airflow 6c from the first intake fan 31 and the second intake fan 32 to the back conveyance path 92 is opened (unblocked). ). That is, when in the open state, the back conveyance path shutter 53 is provided so as not to block the opening H3 formed in the wall W2 leading from the inside of the air passage 21 to the back conveyance path 92.

If the control unit 60 determines in step S12 shown in FIG. 8 that the measurement result obtained from the sensor unit 40 satisfies the predetermined condensation generation condition (in the case of Yes in step S12), then the control unit 60 performs a process as shown in FIG. In step S13, as described above, the heater 11a is driven to generate heat, the first intake fan 31 and the second intake fan 32 are each driven to rotate in the forward direction, and the first exhaust fan 35 is rotated in the forward direction. In addition to stopping the second exhaust fan 36 and the exhaust port fan 38, the back conveyance path shutter 53 is also closed.

As a result, the airflow 6, which is warm air containing heat from the heater 11a, generated by driving the first intake fan 31 and the second intake fan 32 passes through the first intake fan 31 and the second intake fan 32. After reaching the inside of the airflow path 21, the drive is stopped and the airflow 6 hits the first exhaust fan 35 and the second exhaust fan 36, which act as resistance, and bounces back, and then the opening H1 formed in the wall W2 and hits the surface of the conveyance path 91. In addition, a part of the airflow 6 that bounces off the first exhaust fan 35 and the second exhaust fan 36 hits the back conveyance path shutter 53 in the closed state and bounces back, and therefore leaks to the surface of the back conveyance path 92 through the opening H3. This can be suppressed. Thereby, more airflow 6 can be applied to the surface of the conveyance path 91 through the opening H1 formed in the wall W2. Thereby, the temperature of the conveyance path 91 can be further increased in a short time to make it difficult for dew condensation to adhere.

After that, in step S14 shown in FIG. 8, if the control unit 60 determines that the predetermined dew condensation avoidance condition is satisfied (in the case of Yes in step S14), then in step S15, as described above, The first intake fan 31 and the second intake fan 32 are maintained in a state where they are rotated in the forward direction, and the first exhaust fan 35, the second exhaust fan 36, and the first exhaust fan 35, the second exhaust fan 36, and Each of the exhaust port fans 38 is driven to rotate in the forward direction.

As a result, the airflow 5 containing heat from the heater 11a passes through the exhaust duct 22 through the first intake fan 31, second intake fan 32, first exhaust fan 35, and second exhaust fan 36, and from the exhaust port 22e. , are released to the outside of the image forming apparatus 100. Thereby, it is possible to suppress the heat from the heater 11a from being trapped inside the image forming apparatus 100.

For example, if the control unit 60 determines that the predetermined condensation avoidance condition is satisfied in step S14 shown in FIG. When it is determined that the predetermined dew condensation avoidance condition is approached, the control unit 60 may open the back conveyance path shutter 53, as shown in FIG.

As a result, the airflow 6c, which is a part of the airflow 6 that bounced off the first exhaust fan 35 and the second exhaust fan 36, which are acting as resistance to the airflow 6 due to the drive being stopped, is removed from the back conveyance path shutter that is in the open state. 53, passes through an opening H3 formed in the wall W2, and hits the surface of the back conveyance path 92. Therefore, after raising the temperature of the surface of the conveyance path 91 in a shorter time to make it difficult for dew to adhere, the temperature of the surface of the back conveyance path 92 is further increased to make it difficult for dew to adhere. can do.

FIG. 13 is a diagram showing the flow of the airflow 6 when the first exhaust shutter 51, the second exhaust shutter 52, and the back conveyance path shutter 53 are in the closed state in the image forming apparatus 100 according to the third modification of the embodiment. . FIG. 14 shows the flow of the airflow 6 when the first exhaust shutter 51 and the second exhaust shutter 52 are in the closed state and the back conveyance path shutter 53 is in the open state in the image forming apparatus 100 according to the third modification of the embodiment. FIG.

As shown in FIGS. 13 and 14, the image forming apparatus 100 may include a first exhaust shutter 51, a second exhaust shutter 52, and a back conveyance path shutter 53, which can be opened and closed. The driving of the first exhaust shutter 51, the second exhaust shutter 52, and the back conveyance path shutter 53 is controlled by a control unit 60 (see FIG. 5). That is, the control unit 60 switches each of the first exhaust shutter 51, the second exhaust shutter 52, and the back conveyance path shutter 53 between an open state and a closed state.

If the control unit 60 determines in step S12 shown in FIG. 8 that the measurement result obtained from the sensor unit 40 satisfies the predetermined condensation generation condition (in the case of Yes in step S12), then in step S13, the above-mentioned As described above, the heater 11a is driven to generate heat, the first intake fan 31 and the second intake fan 32 are each driven to rotate in the forward direction, and the first exhaust fan 35, second exhaust fan 36, and In addition to stopping the exhaust port fan 38, each of the first exhaust shutter 51, the second exhaust shutter 52, and the back conveyance path shutter 53 is closed (the state shown in FIG. 13).

As a result, the airflow 6, which is warm air containing heat from the heater 11a, generated by driving the first intake fan 31 and the second intake fan 32 passes through the first intake fan 31 and the second intake fan 32. After reaching the inside of the air passage 21, it bounces back by hitting the first exhaust shutter 51 and the second exhaust shutter 52 which are in the closed state. In this way, by closing the first exhaust shutter 51 and the second exhaust shutter 52, it is possible to reduce the amount of airflow 6 leaking from the ventilation path 21 to the exhaust duct 22 during operation in the condensation suppression mode. . Therefore, it is possible to increase the amount of airflow 6 that bounces off the first and second exhaust shutters 51 and 52 in the closed state, and more airflow 6 is transported through the opening H1 formed in the wall W2. can be applied to the surface of the channel 91.

In addition, a part of the airflow 6 that has bounced off the first exhaust shutter 51 and the second exhaust shutter 52 hits the back conveyance path shutter 53 in the closed state and bounces back, so it passes through the opening H3 and reaches the surface of the back conveyance path 92. Leakage can be suppressed. This also allows more airflow 6 to be applied to the surface of the conveyance path 91 through the opening H1 formed in the wall W2.

Thereby, the temperature of the conveyance path 91 can be further increased in a short time to make it difficult for dew condensation to adhere.

For example, if the control unit 60 determines that the predetermined condensation avoidance condition is satisfied in step S14 shown in FIG. When it is determined that the predetermined dew condensation avoidance condition has been reached, the control unit 60 maintains the first exhaust shutter 51 and the second exhaust shutter 52 in the closed state, and closes the back conveyance path shutter 53, as shown in FIG. may be in an open state.

As a result, the airflow 6c, which is a part of the airflow 6 that bounced off the first and second exhaust shutters 51 and 52 that are in the closed state, is not blocked by the back conveyance path shutter 53 that is in the open state, and is not blocked by the wall W2. It passes through the formed opening H3 and hits the front surface of the back conveyance path 92. Therefore, after raising the temperature of the surface of the conveyance path 91 in a shorter time to make it difficult for dew to adhere, the temperature of the surface of the back conveyance path 92 is further increased to make it difficult for dew to adhere. can do.

FIG. 15 shows an image forming apparatus 100 according to a fourth modification of the embodiment, in which the first intake fan 31 rotates in the forward direction, the second intake fan 32 rotates in the opposite direction, and the back conveyance path shutter 53 is in the closed state. It is a figure showing the flow of 6d of airflows at that time. FIG. 16 shows an image forming apparatus 100 according to a fourth modification of the embodiment in which the first intake fan 31 rotates in the forward direction, the second intake fan 32 rotates in the opposite direction, and the back conveyance path shutter 53 is in an open state. FIG.

As shown in FIGS. 15 and 16, the image forming apparatus 100 includes a back conveyance path shutter 53 that can be opened and closed, and the second intake fan 32 rotates in the forward direction and in the reverse direction. It may be possible to switch the rotation direction. The rotation of the second intake fan 32 in the opposite direction is the rotation of the second intake fan 32 such that the airflow blown by the second intake fan 32 hits the conveyance path 91 . The control unit 60 switches the back conveyance path shutter 53 between a closed state and an open state, and switches the rotation direction of the second intake fan 32.

If the control unit 60 determines in step S12 shown in FIG. 8 that the measurement result obtained from the sensor unit 40 satisfies the predetermined condensation generation condition (in the case of Yes in step S12), then in step S13, the above-mentioned As described above, the heater 11a is driven to generate heat, the first intake fan 31 is driven to rotate in the forward direction, and the first exhaust fan 35, second exhaust fan 36, and exhaust port fan 38 are stopped. In addition to this, the second intake fan 32 is driven to rotate in the opposite direction, and the back conveyance path shutter 53 is brought into a closed state (the state shown in FIG. 15).

As a result, the airflow 6d, which is warm air containing heat from the heater 11a, generated by the rotation of the first intake fan 31 in the forward direction passes through the first intake fan 31 and reaches the inside of the air passage 21. Thereafter, the air rebounds by hitting the first exhaust fan 35 and the second exhaust fan 36, which are stopped. Further, as the second intake fan 32 rotates in the opposite direction, the airflow 6 d that bounces off the first exhaust fan 35 and the second exhaust fan 36 actively passes through the second intake fan 32 and enters the conveyance path 91 . hit the surface. Thereby, more airflow 6d can be positively applied to the surface of the conveyance path 91 through the second intake fan 32 rotating in the opposite direction. Therefore, the temperature of the conveyance path 91 can be further increased in a short time to make it difficult for dew condensation to adhere.

Furthermore, since the back conveyance path shutter 53 is in the closed state, a part of the airflow 6d hits the back conveyance path shutter 53 and bounces back, thereby suppressing leakage to the surface of the back conveyance path 92 through the opening H3. be able to. This also allows more airflow 6d to be applied to the surface of the conveyance path 91 through the opening H1 formed in the wall W2.

Thereby, the temperature of the conveyance path 91 can be further increased in a short time to make it difficult for dew condensation to adhere.

For example, if the control unit 60 determines that the predetermined condensation avoidance condition is satisfied in step S14 shown in FIG. If it is determined that the predetermined dew condensation avoidance condition is approached, the control unit 60 may maintain the rotation of the second intake fan 32 in the opposite direction and open the back conveyance path shutter 53, as shown in FIG.

As a result, the airflow 6c, which is a part of the airflow 6d that bounced off the first exhaust fan 35 and the second exhaust fan 36 that are stopped, is not blocked by the back conveyance path shutter 53 that is in the open state, and is not blocked by the wall. It passes through the opening H3 formed in W2 and hits the front surface of the back conveyance path 92. Therefore, after raising the temperature of the surface of the conveyance path 91 in a shorter time to make it difficult for dew to adhere, the temperature of the surface of the back conveyance path 92 is further increased to make it difficult for dew to adhere. can do.

In the image forming apparatus 100 according to the fourth modification of the embodiment shown in FIGS. 15 and 16, the back conveyance path shutter 53 may be omitted, or the first exhaust shutter 51 and the second exhaust shutter 52 may be omitted. The control unit 60 closes both the first exhaust shutter 51 and the second exhaust shutter 52 when a predetermined condensation generation condition is satisfied, and closes the first exhaust shutter 51 when a predetermined condensation avoidance condition is satisfied. and the second exhaust shutter 52 may both be in an open state. Furthermore, the elements appearing in the embodiments and modifications described above may be combined as appropriate to the extent that no contradiction occurs.

5, 5a, 5b: Air current, 6, 6a to 6d: Air current, 10: Fixing device, 11: Heat roller, 11a: Heater, 12: Pressure roller, 21: Air flow path, 22: Exhaust duct, 22e: Exhaust port , 31: first intake fan, 32: second intake fan, 35: first exhaust fan (exhaust fan), 36: second exhaust fan (exhaust fan), 37: exhaust filter, 38: exhaust port fan, 40: Sensor unit, 51: First exhaust shutter (exhaust shutter), 52: Second exhaust shutter (exhaust shutter), 53: Back conveyance path shutter, 60: Control unit, 70: Storage unit, 91: Conveyance path, 92: Back side Conveyance path, 100: Image forming device, 200: Heat dissipation mechanism, H1: Opening, H2a/H2b: Opening, H3: Opening, R1 to R3: Paper conveyance path, W1/W2: Wall

Claims (7)

a heating roller including a heater;
a pressure roller for pressurizing the paper against the heating roller and ejecting the paper;
a conveyance path through which the paper discharged from the heating roller and the pressure roller is conveyed;
a first intake fan provided so that the conveyance path is interposed between the first intake fan and the heating roller;
an exhaust fan provided in an exhaust duct leading to the outside and receiving airflow blown by the first intake fan in a direction opposite to the conveyance path;
a sensor unit that measures at least one of temperature and humidity and outputs a measurement signal indicating the measurement result;
a control unit that controls driving of the heater, the first intake fan, and the exhaust fan;
In the image forming apparatus, the control unit drives the heater and the first intake fan and stops the exhaust fan when the measurement result satisfies a predetermined condensation generation condition. Among the flow paths of the air flow blown by the first intake fan, a closed state in which the flow path of the air flow from the first intake fan to the exhaust fan is blocked; and a closed state in which the air flow flow path from the first intake fan to the exhaust fan is closed. An exhaust shutter that can be switched between an open state and an open state that opens the air flow path,
The image forming apparatus according to claim 1 , wherein the control unit causes the exhaust shutter to be in the closed state when the measurement result satisfies the predetermined dew condensation generation condition. an air passage that guides the airflow blown by the first intake fan to the exhaust duct;
a back surface conveyance path through which the paper discharged from the heating roller and the pressure roller to the conveyance path is conveyed when printing on the back side of the paper;
The image forming apparatus according to claim 1 , wherein the back surface conveyance path is adjacent to the conveyance path and faces the air blow path. Among the flow paths of the air flow blown by the first intake fan, a closed state in which a flow path of the air flow from the first intake fan to the back surface conveyance path is blocked; and a closed state in which the flow path of the air flow from the first intake fan to the back surface conveyance path is closed; a back conveyance path shutter that can be switched between an open state and an open state in which the flow path of the airflow is opened;
The image forming apparatus according to claim 3 , wherein the control unit sets the back conveyance path shutter to the closed state when the measurement result satisfies the predetermined dew condensation generation condition. an air passage that guides the airflow blown by the first intake fan to the exhaust duct;
a second intake fan provided in the air passage so as to face the conveyance passage;
2. The control unit further drives the second intake fan so that the air flow blown by the second intake fan hits the conveyance path when the measurement result satisfies the predetermined condensation generation condition. Or the image forming apparatus according to 2. 3. The image forming apparatus according to claim 1, wherein the predetermined condensation generation condition is when the temperature is less than a predetermined temperature threshold, or when the humidity is greater than or equal to a predetermined humidity threshold. The image forming apparatus according to claim 1 , wherein the control unit drives the heater, the first intake fan, and the exhaust fan when determining that a predetermined dew condensation avoidance condition is satisfied.

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